Characteristics of Glow Discharge at Dielectric Surface

To obtain large-area sheet plasma, direct-current (DC) glow discharge above a diele-ctric surface in argon has been investigated experimentally. The voltage-current characteristics and images of the surface discharge were recorded under coplanar and face-to-face configurations. The effect of the dielectric on the distribution of electric field and the discharge characteristic were discussed. The results showed that the surface discharge in the vicinity of the dielectric is similar for the two configurations, with both similar plasma image and current-voltage characteristic which is dependent upon the operation conditions, but it is different from the classical DC glow discharge due to the influence of the dielectric surface on the electric field and the charge-loss mechanism. A dense sheet plasma can be achieved in both the coplanar and the face-to-face electrode geometry.